Thanks, putting that in the bb-config.php file worked for me! And it seems my settings in the admin area were updated with the new url too.
Hmm, interesting. I did download Hidden Forum, but haven’t activated it. I’ll investigate – thanks.
Thanks, both, for your quick replies.
I tried deleting cookies and clearing cache, as Ipstenu suggests, and lo! I can log in again! I would never have thought of that as a solution …
It would also explain why others can log in; they must be using IE. Much as I love FF, this is very odd behaviour.
Thanks again – I’m delighted this had such a simple solution